1. Field of the Invention
The present invention relates generally to semiconductor packages and, more particularly, to a semiconductor package which is fabricated to include a low temperature co-fired ceramic (LTCC) substrate, and is uniquely configured to have a minimal profile while including one or more semiconductor dies and/or passive elements of various size and thickness.
2. Description of the Related Art
In the electronic arts and, more particularly, in the field of image mobile communications, there is an increasing need for various electronic components which are extremely small and light. In addition to the need for discrete component parts which are of decreased size and weight, there is also a need for an increase in wiring density in order to meet certain functional requirements. In order to meet these particular requirements, there have been developed in the prior art semiconductor packages fabricated through the implementation of a low temperature co-fired ceramic (LTCC) technique.
In the LTCC technique, a substrate is formed at a low temperature in the range of from about eight hundred degrees to one thousand degrees Celsius via the co-firing of ceramic and metal. Through the LTCC technique, a green sheet having a prescribed dielectric constant is formed by mixing glass having a low melting point with a ceramic. Thereafter, a conductive paste in which gold or copper is the primary material is printed and stacked on the green sheet. The LTCC technique for forming a substrate has proven superior to the prior art multi-layer PCB (printed circuit board) technique and the prior art MCM (multi chip module) technique in terms of wiring density and electrical and thermal characteristics. Passive elements, such as a capacitor, resistor, inductor or the like may be imbedded into the LTCC substrate, thereby accomplishing die integration and elevated reliability in a thin, light, and small structure.
However, LTCC substrates as currently known in the prior art possess certain deficiencies which detract from their overall utility. More particularly, in the LTCC technique as currently known, multiple substrate units are typically included in a conventional panel or strip. The strip is eventually cut or singulated in a manner separating the LTCC substrate units from each other, with each separated or singulated substrate unit constituting a portion of a corresponding semiconductor package. However, in the current LTCC technique, there is a susceptibility of warpage in the panel or strip, which creates problems in the manufacturing process for the semiconductor packages including the LTCC substrate units. To combat this problem, panels or strips of reduced size which are less susceptible to warpage are typically used, though such size reduction gives rise to productivity penalties since only a smaller number of semiconductor packages can be fabricated using the reduced size panel or strip.
In addition, in semiconductor packages including LTCC substrates, it is often desirable to mount various types of semiconductor elements (e.g., semiconductor dies and/or passive devices or elements) to the LTCC substrate. The configuration of LTCC substrates as currently known makes the mounting of such semiconductor elements thereto very difficult to control. The present invention addresses and overcomes these and other deficiencies of the current LTCC technique and LTCC substrate formed through the use of the same.